Grocery delivery became a must-have after the acquisition, because grocers largely believed that Amazon would lower store prices and take over delivery, making it inexpensive and easy, potentially stealing away customers.

Grocers began forgoing the typically drawn-out pilot period and multi-year roll outs, and, according to Apoorva Mehta, CEO of Instacart, retailers started calling to launch the service immediately, in as many stores as possible.

In fact, in the six months after the acquisition, Instacart inked several deals with notable grocers:

Aldi struck a deal with Instacart in August, launching in Los Angeles, Atlanta, and Dallas as a pilot.

In early November, Kroger signed a deal with Instacart to roll out grocery delivery for its Ralphs stores in Southern California. Kroger had been in talks with Instacart for years prior, and it'd been offering home delivery for stores through other providers such as Shipt, deliv, and Uber. Amazon's acquisition of Whole Foods likely gave Instacart more credibility from Kroger's perspective, giving it confidence to enter the partnership.

Albertsons entered a partnership with Instacart in late November, with the aim of rolling out Instacart's services in more than 1,800 Albertsons stores by mid-2018.

These partnerships have given Instacart a huge presence in the US, as it now delivers to 66 million US households. The delivery service says its goal is to reach 80% of US households in 2018, up from the 52% it currently services, which may be feasible if its partnerships continue to expand at the same clip as the prior six months. Additionally, Instacart is building on its momentum in the US by eyeing international expansion, starting with Loblaw Cos., Canada's largest grocer, which it's currently in talks with.

Despite concerns that AmazonFresh could replace Instacart's services at Whole Foods, Instacart will likely continue to benefit from this acquisition over the next year, which could possibly establish it as a dominant market leader. At the time of the acquisition, Whole Foods accounted for nearly 10% of Instacart's business, but it also owned a minority stake in the delivery provider.

This made it unlikely for Amazon to eliminate the partnership with Instacart, as it would lower the value of Whole Foods' investment in the company. Although the possibility of Amazon selling its stake and ending its partnership with Instacart still stands, the consequences would no longer be as severe for the delivery provider, given its newly established clout in the space. Additionally, the mounting pressure on grocers to provide delivery services will likely enable Instacart to continue rapidly expanding partnerships over the next year, becoming the preferred provider for many US grocers.